Title: Cholinergic modulation of brain state and visual processing

Abstract The cholinergic system in the basal forebrain is an important component of the neuromodulatory system controlling brain state, and it is thought to play critical roles in regulating arousal and attention. However, its role in modulating sensory processing is not yet well understood. Using electrical stimulation in anesthetized rat and optogenetic activation in awake mice, we found that activation of the cholinergic system causes decorrelation between neurons and increases in response reliability in the primary visual cortex. Quantitative analyses suggest that both of these effects can contribute to enhanced visual processing. Behavioral experiments confirmed that optogenetic activation of basal forebrain cholinergic neurons indeed improves visual discrimination.